Genetic variability of CYP3A4 in a heterogeneous Brazilian population from Maranhão.

Inter-individual variability in drug metabolism may result in adverse drug responses. Pharmacogenetic studies have shown that polymorphisms in drug metabolizing enzymes may contribute to this variability. Among these enzymes, CYP3A4 is responsible for metabolizing over 50% of the clinically used drugs. The Brazilian population is composed of people with Native American, European, and African ancestries, and is therefore considered as one of the most intermixed populations in the world. A thorough knowledge of the genetic frequencies of CYP3A4 allelic variants is useful for the establishment of better pharmacological therapies; therefore, the aim of this study was to describe the polymorphic frequencies for CYP3A4 -392A>G (rs2740574) in a sample population from Maranhão, Brazil. Our results showed that 75.1, 21.9, and 3.0% of the individuals expressed the -392AA, -392AG, and -392GG genotypes, respectively. The -392A and -392G alleles were observed in 86.1 and 13.9% of the population, respectively. Our results reiterate the need for a better understanding of the variations in the genotype and allele frequencies of CYP3A4 -392A>G polymorphisms in various Brazilian regions, in order to elucidate the variability in drug response.

Polymorphisms of p53, GSTM1 and GSTT1, and HPV in uterine cervix adenocarcinoma.

OBJECTIVE: To analyze the participation of glutathione-S-transferase (GST) M1 and T1 polymorphisms associated or not with protein p53 polymorphism at codon 72 and in the presence of HPV in the carcinogenesis of uterine cervix adenocarcinoma. METHODS: Forty-three samples of uterine cervix adenocarcinoma were studied and 86 samples of endocervical cells of women without tumors formed the control group. The presence of HPV was determined in order to genotype the isoforms of p53 at codon 72, GSTM1, GSTM1*0, GSTT1 and GSTT1*0 which were evaluated by the PCR method. RESULTS: HPV was present in 97.67% of the adenocarcinoma cases and in 31.40% of the control group. Statistical analysis showed differences (p = 0.001) and an OR of 113.3 (CI 95%: 13.67-947.14). GSTT1 and GSTT1*0 analysis showed a significant difference between the groups (p = 0.001) with an OR of 4.58 (CI 95%: 2.041-10.28) (p < 0.001) for the presence of GSTT1*0. When it was associated with HPV OR was 6.6 (CI 95%: 0.04-0.50). Analyses of p53 and GSTM1 and GSTM1*0 either alone or associated with HPV were not significant. CONCLUSION: The presence of GSTT1*0 increased the risk for uterine cervix adenocarcinoma development while the allele GSTT1 had a protective action. The other isoforms did not appear to participate in the carcinogenesis of uterine cervix adenocarcinoma.

Detection of Paracoccidioides brasiliensis by PCR in biopsies from patients with paracoccidioidomycosis: correlation with the histopathological pattern.

Paracoccidioidomycosis, a systemic mycosis, is rarely diagnosed in its initial phase and can remain latent for up to 40 years. Although PCR is sensitive for the identification of Paracoccidioides brasiliensis (Pb) in different samples, no study using paraffin-embedded human tissue has been published. The size of the amplicon, the fixation method and the time of the storage may affect the reaction. Recently the more sensitive Primer-Extension-Preamplification (PEP)-Nested-PCR has been used for amplification of small samples. Our aims were to detect Pb in paraffin embedded biopsies using (PEP)-Nested-PCR and to correlate the data with histopathological parameters. Analyses were carried out in 107 biopsies from tegument, lymph node, lung and tongue. The fungal DNA was detected in 29.9% of the biopsies by (PEP)-nested-PCR against 5% of Nested-PCR. The positivity correlated with numbers of fungi and fungal viable cells, and there was no correlation with the granuloma pattern.

Effect of tibolone on cytochrome c oxidase I, beta-2-microglobulin and vascular endothelial growth factor gene expression in the lower urinary tract of castrated rats.

INTRODUCTION: The objective of this study was to evaluate the effect of tibolone on cytochrome oxidase I (COX I), beta-2-microglobulin (B2M) and vascular endothelial growth factor (VEGF) gene expression in the lower urinary tract of castrated rats. These genes are related to cell energy, cellular immunity and vascularization processes. METHODS: Fifty adult castrated rats remained at rest for 28 days. Thereafter they were randomly divided into two groups of 25 animals each. The lower urinary tract (bladder and urethra) was extracted in animals of one group and the other group received tibolone at a dose of 0.25 microg/animal/day for another 28 days followed by removal of the lower urinary tract. Total RNA was extracted from animals of both groups, forming two pools. After RT-PCR (reverse transcriptase polymerase chain reaction), expression of COX I, B2M and VEGF genes was evaluated by agarose gel electrophoresis, visualized by UV illumination. RESULTS: Expression of the three genes (COX I, B2M and VEGF) was greater in the group treated with tibolone. CONCLUSION: The use of tibolone increases the expression of COX, B2M and VEGF genes in the lower urinary tract as compared with that in castrated rats.

Tamoxifen down-regulates CaMKII messenger RNA levels in normal human breast tissue.

Tamoxifen was proven to reduce the incidence of breast cancer by 49% in women at increased risk of the disease in the Breast Cancer Prevention Trial. In order to identify potential candidates to explain the preventive effect induced by tamoxifen on breast cancer, normal breast tissue obtained from 42 fibroadenoma patients, randomly assigned to receive placebo or tamoxifen, was analyzed by the reverse Northern blot and RT-PCR techniques. The cDNA fragments used on Northern blot membranes were generated by the Human Cancer Genome Project funded by the Ludwig Institute for Cancer Research and FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil). Total RNA was obtained from normal breast tissue from patients with clinical, cytological and ultrasound diagnosis of fibroadenoma. After a 50-day treatment with tamoxifen (10 or 20 mg/day) or placebo, normal breast tissue adjacent to the tumor was collected during lumpectomy with local anesthesia. One differentially expressed gene, Calcium/calmodulin-dependent protein kinase II (CaMKII), was found to be down-regulated during TAM treatment. CaMKII is an ubiquitous serine/threonine protein kinase that has been implicated in the diverse effects of hormones utilizing Ca2+ as a second messenger as well as in c-fos activation. These results indicate that the down-regulation of CaMKII induced by TAM might represent alternative or additional mechanisms of the action of this drug on cell cycle control and response to hormones in normal human breast tissue.